KLA-Tencor was formed in April 1997 through the merger of KLA Instruments (KLA) and Tencor Instruments (Tencor), two long-time leaders in the semiconductor equipment industry. Prior to the merger, both businesses served a segment of the inspection and metrology area; with KLA focused on defect inspection solutions and Tencor placing its emphasis on metrology solutions. Merging together in a one-to-one stock swap valued at $1.3 billion, KLA-Tencor became the most important process control player in the industry, bringing to market a complete line of yield management products and services from a single company.